Electric plug



F. PFEIFFER ELECTRIC PLUG Fume 2l, 1-1

Filed Oct. 30, 1936 2 Sheets-Sheet l Attorneys je 2l,

F. PFEIFFER ELECTRI C PLUG- Filea oct. so, 195e 2 sheets-sheet 2 Attorneys Patented June 21, 1938 UNITED STATES PATENT OFFICE '2' claims.

The present invention relates to electric plugs of the two-part type and has for its principal object to provide means for securing the parts 'of the plug together against accidental displacement.

A further object is to provide an electric plug of this character of simple'and practical construction, which is efficient and reliable in performance, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages desired in the details of construction and operation as more fully and hereinafter described and claimed, ref-` erence'being had to the accompanying drawings forming part thereof, wherein like numerals refer to like parts throughout and in which:

Figure 1 is aside elevational vview of a twopart plug in assembled position with the connecting ring shown in section. v

Figure 2 is a top plan view.

Figure 3 is a top plan view of the female or bottom section of the plug having its flange formed with opposed at surfaces.

Figure 4 is a similar view of a modified form of the female part of the plug. p

Figure 5 is a side elevational view ofa twopart plug showing a modified form of connector ring in section.

Figure 6 is a bottom plan view of the male or upper section of the plug showing the lugs formed on the lower edge of the connector ring.

Figure 'l is a fragmentary sectional view of the female part of the plug and connector ring.

Figure 8 is a side elevational view of the form of connector ring shown in Fig. 5.

Figure 9 is a side elevational of the connector ring shown in section in Fig. 7.

Referring now to the drawings in detail, wherein for the purpose of illustration I have disclosed several preferred embodiments of invention, the numeral 5 designates the female or lower part of a two-part electric plug having its upper surface provided with the usual recesses 6 for receiving the prongs 'I of the upper or male part 8 of the plug.

In the form of invention illustrated in Figure 1 of the drawings the part 5 is formed at its upper edge with an annular flange 9 having a groove I9 formed in the outer surface thereof and provided at diametrically opposed side with at surfaces II. v

The upper part of the plug 8 is likewise formed with an annular flange I2 at its lower edge, said ange likewise being formed with an annular groove I3 in its outer surface. The part 8 is provided with a connector ring Ill which includes a skirted portion I5 positioned outwardly of the ilanges 9 and I2, the inner surface of said skirted portion being formed with vertically spaced ann nular ribs It and Il seated respectively in the grooves I 3 and I9 of the upper and lower parts of the plug. .The upper edge of the'ring I5 is formed with an inturned ange I8 which overlies and rests upon the iiange I2 of the upper part of the plug. The lower rib I1 formed on the' skirted portion I5, is interrupted, as shown in Figures '7 and 9 of the drawings to provide a plurality of rib sections I9 at the diametrically opposite sides of the ring whereby it will be apparent that in connecting the parts 8 and 5 of the plug that by aligning the sections I9 of the rib with the at sides II of the part E of the plug said rib sections I9 4will enter the groove III and upon a rotation ofthe ring I5 will secure the parts of the plug against accidental separation.

I The ange I9 aft-the top of the ring is formed with cut out notches 29 at diametrically opposite sides of the ring to accommodate upstanding lugs 2i formed on the flange I2 of the upper part 8 of the plug. The lugs 2| constitute stops engaging with the ends of the cut out portions 2U to limit the rotation of the rings I5 whereby to indicate and secure the ring in its locked position.

In the modified form of the invention illustratedin Figure 4 the lower part 5 of the plug may be formed with curved notches 22 in the ange 9 thereof in lieu of the fiat sides II.

In the modified form of the invention illustrated in Figures 5, 6 and 8 the groove may be 35 omitted from'the flange 9 of the lower part 5 of the plug and the ribs I9 omitted from the skirted portion I5 of the ring and in lieu thereof the lower edge of the skirted portion I5 is formed with inturned lugs 2.8 at 'diametrically opposite sides of the ring for engaging under the lower edge of the flange 9.

It is believed the details of construction and operation of the device will be readily understood from the foregoing without further detail 45 explanation thereof.

1. An electric plug including male and female parts, a connector for said parts comprising a ring member rotatably carried 'by one part of the 50 plug said part of the plug being provided with a flange having an annular groove in its perimeter, said ring member including a skirted portion,

'an annular rib on the inner surface of said skirtmember against removal from said part of the plug, an interrupted annular ange on the other part of the plug and inter-engaging means between the ring member and a last named ilange for rotatably connecting same, said inter-engaging means comprising an annular groove ln the perimeter of the last named ange and an inter'- rupted rib on the inner surface of the ring member seated in said last named groove and adapted for releasing this said other part of the plug from the ring member upon a predetermined rotating movement of the ring member.

2. An electric plug including male and female parts; a connectorfor said parts comprising. a ring member mounted on one part of the plug,

said part of the plug having a flange provided' with an annular groove in its perimeter, said ring member also having a -ilange overlying-the ilange of the plug to rotatably secure the ring member aimais thereto, said ring member including a skirted portion, an annular rib on the inner surface of said skirted portion seated in said groove, an interrupted annular iiange on the other part of the plug, inter-engaging means between the ring member and the last named flange for rotatably connecting the same, said inter-engaging means comprising an annular groove in the perimeter of the last named ange and an interrupted rib on the inner surface of the ring member seated in said last named grooveand adapted for releasing said other part of the plug from the ring member upon a predetermined. rotating movement of a ring member andfcooperating means between the first part of the plug and the ange on the ring member limiting rotation of the ring member.

FREDERICK Pm. 

